Anti-counterfeiting features and methods of fabrication and detection

Abstract

Aspects of the present disclosure include an anti-counterfeiting pattern that is identifiable by sheet resistance mapping metrology, a method of fabricating such an anti-counterfeiting device, and a method of detecting such an anti-counterfeiting device by imaging the pattern with sheet resistance mapping metrology. This abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

What is claimed is: 
     
       1. An anti-counterfeiting device, comprising:
 a structure having an anti-counterfeiting pattern, wherein the anti-counterfeiting pattern comprises variations of sheet resistance, wherein the anti-counterfeiting pattern is identifiable as an anti-counterfeiting feature by sheet resistance mapping metrology. 
 
     
     
       2. The device of  claim 1 , wherein the anti-counterfeiting pattern is invisible to unaided human eyes. 
     
     
       3. The device of  claim 1 , wherein the structure is formed in a device layer where device features are formed. 
     
     
       4. The device of  claim 1 , wherein the structure is formed on top of a device layer where device features are formed. 
     
     
       5. The device of  claim 2 , wherein the anti-counterfeiting pattern comprises lines having a linewidth less than 2 microns. 
     
     
       6. The device of  claim 1 , wherein the anti-counterfeiting pattern is in a form of recognizable characters. 
     
     
       7. The device of  claim 1 , wherein the anti-counterfeiting pattern is a pattern similar to surrounding device features that is deliberately shifted and/or rotated. 
     
     
       8. The device of  claim 1 , wherein the anti-counterfeiting pattern is a bar code. 
     
     
       9. The device of  claim 1 , wherein the anti-counterfeiting pattern is characterized by a specific gradient of sheet resistance. 
     
     
       10. The device of  claim 1 , wherein the sheet resistance mapping metrology includes Eddy current metrology or Terahertz microprobe-based metrology. 
     
     
       11. The device of  claim 1  wherein the structure having the anti-counterfeiting pattern is integrated into a touch screen sensor, smart window, electromagnetic interference (EMI) shield, transparent heater, or solar panel. 
     
     
       12. A method for detecting an anti-counterfeiting device having an anti-counterfeiting pattern, wherein the anti-counterfeiting pattern comprises variations of sheet resistance, the method comprising imaging the anti-counterfeiting pattern comprising the variations of sheet resistance with a sheet resistance mapping metrology system. 
     
     
       13. The method of  claim 12 , wherein the sheet resistance mapping metrology includes Eddy current metrology or Terahertz microprobe-based metrology. 
     
     
       14. The method of  claim 12 , wherein the anti-counterfeiting pattern comprises lines characterized by a linewidth less than 2 microns. 
     
     
       15. The method of  claim 12 , wherein the anti-counterfeiting pattern is integrated into a sample in the form of a touch screen sensor, smart window, electromagnetic interference (EMI) shield, transparent heater, or solar panel. 
     
     
       16. The method of  claim 12 , wherein the imaging of the anti-counterfeiting pattern comprising the variations of sheet resistance with a sheet resistance mapping metrology system provides a sheet resistance map, the method further comprising identifying the anti-counterfeiting pattern from the sheet resistance map. 
     
     
       17. A method of fabricating an anti-counterfeiting device, the method comprising:
 forming a structure over a substrate, wherein the structure has an anti-counterfeiting pattern, wherein the anti-counterfeiting pattern comprises variations of sheet resistance, wherein the anti-counterfeiting pattern is identifiable as anti-counterfeiting features by sheet resistance mapping metrology. 
 
     
     
       18. The method of  claim 17 , wherein forming the structure over the substrate comprises providing a photosensitive layer on a conductive layer over the substrate, patterning and developing the photosensitive layer to form a patterned photosensitive layer, etching and removing portions of the conductive layer exposed from the photosensitive layer and the photosensitive layer to form the structure with the anti-counterfeiting pattern. 
     
     
       19. The method of  claim 17 , wherein forming the structure over the substrate includes disposing a photo-sensitive material over the substrate, developing the photo-sensitive material to produce a mesh pattern in the developed photo-sensitive material and using the developed photo-sensitive material includes forming a layer of conductive material over the developed photo-sensitive material and onto portions of the substrate exposed by openings in the developed photo-sensitive material, and removing the photo-sensitive material leaving behind conductive material on the substrate at the portions corresponding to the openings. 
     
     
       20. The method of  claim 17 , wherein forming the structure over the substrate includes applying a pattern of conductive material to a surface of the substrate using inkjet technology. 
     
     
       21. The method of  claim 17 , wherein forming the structure over the substrate includes applying a pattern of conductive material to a surface of the substrate using gravure printing technology. 
     
     
       22. The method of  claim 17 , wherein forming the structure over the substrate includes patterning a layer of metal over the substrate. 
     
     
       23. The method of  claim 22 , wherein the layer of metal is patterned by laser ablation. 
     
     
       24. The method of  claim 17 , wherein forming the structure over the substrate includes laser-assisted deposition or etch. 
     
     
       25. The method of  claim 17 , wherein forming the structure over the substrate includes depositing metal through a stencil mask. 
     
     
       26. The method of  claim 17 , the anti-counterfeiting pattern comprises lines characterized by a linewidth that is less than 2 microns. 
     
     
       27. The method of  claim 17 , wherein the anti-counterfeiting pattern is integrated into a sample in the form of a touch screen sensor, smart window, electromagnetic interference (EMI) shield, transparent heater, or solar panel. 
     
     
       28. The method of  claim 17  wherein the anti-counterfeiting pattern is invisible to unaided human eyes.